Cross Country Skiing Workout

Instead of plodding away on the same old piece of cardio equipment all winter long, hit the slopes for some cross-country skiing. You can burn 700-plus calories in a single hour, and push your heart rate into the sweet spot between aerobic and anaerobic zones (an optimal way to burn fat). Pete Swenson, coach of the U.S. Ski Mountaineering team, tells us how to get primed to blaze fresh tracks—and incinerate calories.